制备了多种BrФnsted酸性离子液体,分别将其作为催化剂用于衣康酸酯化反应,考察其催化性能与结构的关系。筛选对比表明三乙胺类离子液体具有较好的催化性能及重复使用性,由FT-IR、NMR对其进行了表征测定。以离子液体[HSO3-pTEA]pTSA为催化剂合成衣康酸二正丁酯,在重复使用7次后催化所得酸转化率为96.5%。优化工艺条件下得酸转化率为98.8%,酯收率为96.7%:以离子液体[HS03-pTEA]HSO4为催化剂合成衣康酸二异辛酯,在重复使用7次后催化所得酸转化率为95.2%。优化工艺条件下得酸转化率为98.7%,酪收率为96.3%。
Several BrФnsted acidic ionic liquids (ILs) were synthesized, and using these prepared ILs as catalysts, the itaconic acid esterifications were investigated. The results show that, among those various kinds of ILs prepared, the triethylamine ILs have the highest catalytic activity and reused-life, and then they were characterized by FT-IR and NMR. Using the prepared acid ionic liquid [HSO3-pTEA]pTSA as catalyst for the synthesis of the dibutyl itaconate (DBIA), and under the optimized synthesis conditions, the itaconic acid conversion of 98.8% and the DBIA ester yield of 96.7% can be reached, respectively. Moreover, the catalyst [HSO3-pTEA]pTSA is immiscible with the product and can be reused for 7 times without any disposal; during the reutilizations, the itaconic acid conversion can still keep above 96.5%. Furthermore, using the prepared [HSO3-pTEA]HSO4 as catalyst for the synthesis of diisooctyl itaeonate (DOIA), and under its optimized reaction conditions, the itaconic acid conversion of 98.7% and the DOIA ester yield of 96.3% can be obtained, respectively. The catalyst [HSO3-pTEA]HSO4 can also be reused for 7 times without any disposal and its itaconic acid conversion can keep above 95.2%.